Downhole tools such as actuators, for example, often use downhole hydrostatic pressures to create forces necessary to actuate the actuator. The actuator has a chamber that stores atmospheric pressure. The chamber includes an adjustable volume cavity that when exposed to downhole hydrostatic pressure is compressible to a smaller volume. Actuation is prevented from initiating until the chamber is positioned in a desired downhole location at which point the actuation is triggered. During compression, the actuator causes relative motion between portions thereof that is utilized in the actuation.
Downhole hydrostatic pressures, however, can be so great that the walls that define the pressure cavity of the chamber can fail due to crushing or bursting depending upon the direction in which the hydrostatic pressure is applied. As such, the art may be receptive of pressure chambers with improved resistance to over pressure failures.